Development of cytotoxic antibodies following renal allograft transplantation is associated with reduced graft survival due to chronic vascular rejection.

We prospectively followed 64 patients who had had no cytotoxic antibodies prior to first cadaveric renal allograft transplantation for post-transplant antibodies. During a mean follow-up period of 62 months (range 45-92) cytotoxic antibodies developed in 36 patients (56%). Sixteen grafts were lost due to chronic vascular rejection in the group of patients who developed antibodies compared to two in those who remained antibody negative, P < 0.01. Renal function was worse in the antibody-positive group, median serum creatinine 215 mumol/l (131-256) (interquartile range) versus 111 mumol/l (98-127) in the antibody-negative group, P = 0.002, and creatinine clearance 39 ml/min (25-55) versus 90 ml/min (55-104), P < 0.001. There were no significant differences in immunosuppressive protocol, HLA-mismatching, blood transfusion history, the number of acute rejection episodes, mean arterial blood pressure, or proteinuria between the groups. The presence of cytotoxic antibodies predated the classical manifestations of chronic vascular rejection. This suggests that humoral mechanisms may play a role in the development of chronic vascular rejection.